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Biomedical subjects

P Chu

Publications and source records attributed to P Chu.

99 records · Page 6Linked to original sources

Plasma lipid and lipoprotein response to fat feeding in alcoholic liver disease.

Serum lipids and lipoproteins were analyzed after an overnight fast, and following a fatty meal in 10 patients with cirrhosis, 5 with fatty liver, and 5 normal subjects. Cirrhotic patients were divided into two groups of five on the basis of serum lecithin-cholesterol acyltransferase activity. Fasting triglyceride levels were similar in all four groups. In all but cirrhotic patients with low lecithin-cholesterol acyltransferase activity, most fasting triglyceride was found in very low density lipoproteins; in the latter group, most of it was found in low density lipoproteins. We confirmed that patients with fatty liver have a higher serum triglyceride response to fat feeding than normal subjects, but we did not find higher levels in cirrhotic patients. Cirrhotic patients with "normal" lecithin-cholesterol acyltransferase activity had a normal triglyceride response to dietary fat. In patients with cirrhosis and low lecithin-cholesterol acyltransferase activity, the increase in triglyceride was less than in normal subjects. In this group, most of the extra triglyceride was carried in low density lipoprotein, and not in chylomicrons and very low density lipoprotein, as in the other groups.

Adult↗

Psoriasis associated with human immunodeficiency virus in an infant.

Psoriasis is commonly reported in association with HIV in adults. A 3-month-old girl with HIV presented with a widespread eruption and was diagnosed with psoriasis. This is the first infant reported with psoriasis in association with HIV infection. The relationship between the two entities is discussed, as is the role of treatment with zidovudine.

Female↗

Occupant perception of indoor air and comfort in four hospitality environments.

This article reports on a survey of customer and staff perceptions of indoor air quality at two restaurants, a billiard hall, and a casino. The survey was conducted at each environment for 8 days: 2 weekend days on 2 consecutive weekends and 4 weekdays. Before and during the survey, each hospitality environment satisfied ventilation requirements set in ASHRAE Standard 62-1999, Ventilation for Acceptable Indoor Air. An objective of this study was to test the hypothesis: If a hospitality environment satisfies ASHRAE ventilation requirements, then the indoor air is acceptable, that is, fewer than 20% of the exposed occupants perceive the environment as unacceptable. A second objective was to develop a multiple regression model that predicts the dependent variable, the environment is acceptable, as a function of a number of independent perception variables. Occupant perception of environmental, comfort, and physical variables was measured using a questionnaire. This instrument was designed to be efficient and unobtrusive; subjects could complete it within 3 min. Significant differences of occupant environment perception were identified among customers and staff. The dependent variable, the environment is acceptable, is affected by temperature, occupant density, and occupant smoking status, odor perception, health conditions, sensitivity to chemicals, and enjoyment of activities. Depending on the hospitality environment, variation of independent variables explains as much as 77% of the variation of the dependent variable.

Air Pollution, Indoor↗

Increased nitric oxide production in hypotensive hemodialysis patients.

A subset of patients on long-term hemodialysis have sustained hypotension, defined as a predialysis systolic pressure of < 100 mmHg. To determine the role of nitric oxide (NO), an important vasodilator, in this condition, the authors measured the plasma levels of nitrite (NO2-) and nitrate (NO3-), the known NO metabolites taken as an index of NO production, in 10 hypotensive patients on long-term hemodialysis. None of them had diabetes, cirrhosis of the liver, congestive heart failure, or infection. Fifteen age and gender-matched normotensive patients on hemodialysis were selected as control subjects. Measurements of plasma levels of nitrite and nitrate based on the Greiss reaction were made. There was no significant difference in hematocrit, serum intact parathyroid hormone, total calcium, inorganic phosphorus, albumin, heart rate, cardiac index, or interdialysis weight gain between these two groups. Plasma nitrite and nitrate levels did not correlate with either predialysis serum creatinine or blood urea nitrogen. The mean arterial pressure (MAP) was significantly lower and plasma nitrite and nitrate levels were significantly higher in chronic hypotensive patients than in normotensive patients (MAP: 68.30 +/- 3.24 mmHg vs 95.20 +/- 2.44 mmHg, p < 0.001; plasma nitrite and nitrate: 72.49 +/- 14.41 mumol/L vs 36.42 +/- 5.45 mumol/L, p < 0.05). In addition, MAP from hypotensive and normotensive patients on hemodialysis was inversely correlated with plasma levels of nitrite and nitrate (r = -0.54, p < 0.01). It was concluded that enhanced NO production in this subset of patients on hemodialysis may contribute to their chronic hypotension.

Adult↗

Prediction of dry weight through changes in blood volume and plasma cyclic 3',5'-guanosine monophosphate in patients under maintenance hemodialysis.

Dry weight evaluation is generally made from clinical observation of body weight (BW) changes, edema, blood pressure, and chest radiograph. In fact, 25-50% of patients on chronic hemodialysis had an incorrectly determined dry weight. To predict dry weight, twenty stable patients on regular hemodialysis were enrolled to investigate the correlation among dry weight, hematocrit, blood volume (BV), and vasoactive hormones including plasma renin activity (PRA), aldosterone (PA), and cyclic 3',5'-guanosine monophosphate (cGMP) values. BV was estimated by an infrared light reflection method. PRA, PA, and plasma cGMP were determined by commercial radioimmunoassay kits. The results showed significantly decreasing plasma cGMP values toward the end of hemodialysis compared with before hemodialysis (15.76 +/- 3.56 pmol/ml vs 33.57 +/- 3.98 pmol/ml; p < 0.05). A significant correlation exists between changes in plasma cGMP values and BV (p < 0.05). In addition, no significant correlation exists between changes in plasma cGMP and BW. A good correlation was found between changes in BV and hematocrit throughout dialysis (r = -0.774; p < 0.001). PRA and PA values predict neither BV nor BW changes. All patients were treated to attain a further ultrafiltration of 0.5 to 1.0 L after reaching dry weight, and we found that the critical point in blood pressure drop occurred when BV decreased by 8% or when plasma cGMP values decreased by 50% from their initial values. Continuous BV monitoring with infrared light reflection and detecting of cGMP throughout hemodialysis could help predict dry weight and avoid dialysis hypotension.

Blood Volume↗

Effect of erythropoietin on neutrophil chemiluminescence in hemodialyzed patients.

Erythropoietin (EPO) has been used widely for correcting anemia in hemodialyzed (HD) patients. Enhancement of phagocytic function during EPO treatment of HD patients has been studied, but no data have been available on the effect of EPO on neutrophil chemiluminescence (CL) after challenge with phorbol myristate acetate (PMA). CL was measured in prehemodialysis whole blood samples from 15 stabilized patients and 15 normal healthy control subjects (C) after challenge with PMA. Before EPO treatment, CL was noted to be significantly higher in HD patients than in C, which changed significantly after 5 weeks of treatment (Rx) and continued for 13 weeks of Rx. There was a significant increase in hematocrit in these HD patients after 5 weeks that persisted until the 13th week. It was concluded that there is a significant decrease in whole blood CL in response to challenge with PMA during correction of anemia in HD patients treated with EPO. This study demonstrated that EPO could decrease enhanced PMA-activated reactive oxygen metabolite production and suggested that this decrease may protect against tissue damage, including red blood cell hemolysis in the uremic milieu.

Adult↗

Neuroleptic dosing in Asian and Hispanic outpatients with schizophrenia.

Recent studies suggest that minorities may have higher plasma levels caused by ethnic variations in pharmacokinetics under standard neuroleptic treatment; they would be at increased risk for extrapyramidal side effects and more likely to be treatment noncompliant. This study examined the prescribing pattern of antipsychotic medication to minority schizophrenics in outpatient psychiatric programs developed to meet their treatment needs. A computer search was conducted of registered clients in a Hispanic and Asian outpatient clinic(s). Hispanic and Asian patients with schizophrenia were identified and for purposes of comparison, a third sample of consecutively drawn outpatients with a diagnosis of "schizophrenia" registered in the outpatient clinic proper were selected. All outpatient medical records were secured and neuroleptic dosing patterns extracted and quantified. Neuroleptic doses were converted to chlorpromazine equivalents and corrected for body weight to a standard of 68 kg. One way analysis of variance procedures were used to compare both the actual and standardized neuroleptic doses across the three samples and revealed a significant main effect for both actual (p < 0.05) and standardized dose (p < 0.05). With regard to the former secondary analysis yielded significant differences between the clinic sample and the Hispanic (p < 0.05) and Asian (p < 0.05) samples, which did not differ significantly from each other but which received significantly less drugs than the other patient population. These results were similar to the standardized dose comparison. The findings replicate previous inpatient reports and have implications for cross-cultural treatment programs.

Adult↗

In vitro maintenance and retroviral transduction of human myeloma cells in long-term marrow cultures.

One objective of clinical gene marking trials in multiple myeloma (MM) is to determine the extent to which relapse after stem cell transplant is attributable to contamination of the autograft with myeloma cells. A requirement in these studies is ex vivo genetic marking of malignant cells present in autografts which are derived from patients exposed to significant prior chemotherapy. We evaluated gene marking of cloonogenic myeloma cells in marrow aspirates from 14 patients with MM. To effect gene transfer we utilized a long-term marrow culture (LTMC) system previously shown to facilitate gene transfer into a spectrum of hematopoietic progenitor and stem cells. Transduction of cells in LTMC was performed by multiple supernatant exposure. At LTMC initiation and after 21 days of culture malignant cells were assessed by morphology, flow cytometry, and polymerase chain reaction (PCR). The mean number of day 21 LTMC adherent layer-derived granulocyte/macrophage progenitors as a percentage of the original inoculum was within the normal range for this technique. The efficiency of transduction of normal hematopoietic progenitors as determined by the number of colonies positive for proviral DNA by PCR, G418 resistance, and X-gal staining was also within the expected range; 65%, 44% and 23%, respectively. Thus, there was no evidence that prior chemotherapy exposure or malignant cell contamination compromised cell survival or gene transfer efficiency in LTMC. All patients retained plasma cells in LTMCs for the duration of the 21-day culture period. Molecular analysis confirmed the persistence of clonal IgVH gene rearrangements in day 21 LTMC-derived DNA from 6 of 12 informative patients (50%). PCR using allele-specific primers when available confirmed the specificity of IgVH rearrangements for the myeloma clone. In 2 of the 14 patients, expansion of clonogenic cells was demonstrated in LTMC. In both cases there was strong evidence for transfer of reporter genes (neo and LacZ) into the myeloma clone: morphologically abnormal G418-resistant colonies demonstrated intense staining for beta-galactosidase, and cytospin preparations showed 100% plasma cells with monoclonal heavy and light chain restriction. In one patient, individual colonies positive for beta-galactosidase bore a cytogenetic abnormality characteristic of the patient's myeloma clone. PCR of DNA from pooled plasma cell colonies using tumor-specific CDR3 primers was positive. Our results demonstrate the maintenance of myeloma cells in vitro for up to 21 days in LTMC. They further illustrate that these cells can be genetically marked using transduction protocols currently being tested in clinical trials of hematopoietic cell gene transfer.

Antineoplastic Agents, Alkylating↗